scholarly journals Bridges over the River Rhine

2020 ◽  
Author(s):  
Michael Müller ◽  
Wolfgang Eilzer ◽  
Rafael Rodriguez
Keyword(s):  
Heavy Traffic ◽  
Suspension Bridge ◽  
Bridge Engineering ◽  
Assessment Process ◽  
Actual Condition ◽  
Suspension Bridges ◽  
River Rhine ◽  
Starting Point ◽  
Wide Range ◽  
Cable Stayed Bridges

Today the total length of the federal trunk highway roads in Germany is about 50,000 km being one of the densest traffic in whole Europe. Among these are approximately 40,000 bridges with a total area of 30 million. Square meters. Fifty percent of these bridges were built in the years between 1960 to 1980. At that time these bridges were mainly designed according to German Standard DIN 1072 for bridge class SLW 60 (60 ton truck). Based on the traffic given at those times, no fatigue checks were required. This assumption seemed fair enough because the massive increase, especially in heavy traffic, could not have been anticipated.  Since the mid-20th century until our days, the bridges over the river Rhine have set a milestone on the history of bridge engineering. Some contributions from the team led by Fritz Leonhardt and Wolfhart Andrä, such as the Cologne-Rodenkirchen suspension bridge, the series of steel bridges with continuous webs developed in the 60´s decade, the Düsseldorf cable stayed bridges family, the widenings and retrofitings of the 80´s decade, or the most recent contributions, encompass widely different typologies and periods and provide valuable learnings. Their preservation, retrofit or eventual replace if necessary, entail an important challenge for the present and future. The starting point of such a strengthening or eventual replacement is always the assessment of the existing bridge under consideration of its actual condition, the prognosticated loads and requirements of future utilization. This assessment process and rating of existing structures was regulated by the German government in 2012 in the “Nachrechnungs”- guidelines. The result of such an assessment is the basis of any further decision about the future of a structure, whether it will be rehabilitated, retrofitted or replaced.   The presentation will focus on the experiences gained under the new guideline and the wide range of engineering services involved in such a rehabilitation planning, using the examples of the Suspension bridges over the River Rhine at Emmerich and Köln-Mühlheim, and will show the specific experience gained through these strengthening projects, but also a short overview about the new cable-stayed bridges in Leverkusen and Duisburg that are built under the premise to maintain traffic for 2 of the most importante highways in Germany.

Research on Dynamic Characteristics for Large Span Cable-Stayed Suspension Bridges with CFRP Cables

2013 ◽  
Vol 683 ◽  
pp. 845-850
Author(s):  
Rong Gui Liu ◽  
Guo Ying Feng ◽  
Bei Chen
Keyword(s):  
Dynamic Characteristics ◽  
Natural Vibration ◽  
Natural Frequencies ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Bridge Structure ◽  
Reinforced Plastics ◽  
New Type ◽  
Carbon Fibre Reinforced Plastics ◽  
Cable Stayed Bridges

Cable-stayed suspension bridge with Carbon Fibre Reinforced Plastics(CFRP) cables is a new type of bridge structure. To study the dynamic characteristics for this kind of bridges, and its differences from cable-stayed bridges of the same span level, finite element dynamic modle of a Cable-stayed suspension bridge with main span of 1488 meters is established and a series of calculations is done. The results show that, natural frequencies of cable-stayed suspension bridges with CFRP cables are relatively small, integral frequencies are stepped and discontinuous; Its modes are centralized and the natural vibration modes show a lot of coupling; The natural frequencies of this kind of bridges are smaller than cable-stayed bridges of the same span level, the entire stiffness decreased.

Static Deformational Behaviors of Cable-Stayed Suspension Bridge and its Simplified Material Cost Model

2014 ◽  
Vol 501-504 ◽  
pp. 1221-1227 ◽  
Author(s):  
Fei Jin Zhang ◽  
Li Li Nie ◽  
Hong You Cao
Keyword(s):  
Cost Model ◽  
Suspension Bridge ◽  
Design Stage ◽  
Suspension Bridges ◽  
Suspension Systems ◽  
Material Cost ◽  
Preliminary Design Stage ◽  
Live Loads ◽  
Bridge Type ◽  
Cable Stayed Bridges

Cable-stayed suspension bridge is an unconventional bridge type with a bridge typology based on the combination of both cable-stayed and suspension systems. In this paper, the static behaviors of cable-stayed suspension bridge were revealed from the viewpoint of the structural deformational characteristics under different kinds of live loads. To more clearly illustrate these characteristics, the simplified analytical method based on the simplified analytical solutions for cable-stayed bridges and suspension bridges were adopted in the derivations. Furthermore, the simplified material cost model based on allowable stress method for cable-stayed suspension bridge was also proposed for researchers and designers to adopt in preliminary design stage.

A new two-node catenary cable element for the geometrically non-linear analysis of cable-supported structures

2010 ◽  
Vol 224 (6) ◽  
pp. 1173-1183 ◽  
Author(s):  
M-G Yang ◽  
Z-Q Chen ◽  
X-G Hua
Keyword(s):  
Structural Parameters ◽  
Flexible Structures ◽  
Suspension Bridge ◽  
Linear Analysis ◽  
Suspension Bridges ◽  
Tangent Stiffness Matrix ◽  
Long Span ◽  
Tension Structures ◽  
Non Linear ◽  
Cable Stayed Bridges

This article presents a geometrically non-linear finite-element method for an accurate and efficient analysis of spatial cable structures. A two-node catenary cable element is formulated accurately considering the effect of self-weight of cable element. The tangent stiffness matrix of the cable element is derived as an accurate explicit expression of structural parameters and the nodal forces of the cable element are then also analytically calculated. Pre-stress in the cable element may be considered in the formulation. Three classical numerical examples are first provided to show the accuracy and efficiency of this method and the developed method is then applied to construction stage simulation in order to determine the erection parameters of a suspension bridge through progressive non-linear analysis. The cable element proposed can be conveniently used for the geometric non-linear analysis of flexible structures such as long-span suspension bridges, cable-stayed bridges, and tension structures.

Control of Vibrations due to Moving Loads on Suspension Bridges

2006 ◽  
Vol 11 (3) ◽  
pp. 293-318 ◽  
Author(s):  
M. Zribi ◽  
N. B. Almutairi ◽  
M. Abdel-Rohman
Keyword(s):  
Bridge Deck ◽  
Suspension Bridge ◽  
Lyapunov Theory ◽  
Dynamic Responses ◽  
Suspension Bridges ◽  
Control Force ◽  
Moving Loads ◽  
Hydraulic Actuator ◽  
Long Span ◽  
Suspended Cables

The flexibility and low damping of the long span suspended cables in suspension bridges makes them prone to vibrations due to wind and moving loads which affect the dynamic responses of the suspended cables and the bridge deck. This paper investigates the control of vibrations of a suspension bridge due to a vertical load moving on the bridge deck with a constant speed. A vertical cable between the bridge deck and the suspended cables is used to install a hydraulic actuator able to generate an active control force on the bridge deck. Two control schemes are proposed to generate the control force needed to reduce the vertical vibrations in the suspended cables and in the bridge deck. The proposed controllers, whose design is based on Lyapunov theory, guarantee the asymptotic stability of the system. The MATLAB software is used to simulate the performance of the controlled system. The simulation results indicate that the proposed controllers work well. In addition, the performance of the system with the proposed controllers is compared to the performance of the system controlled with a velocity feedback controller.

Discovery of Antibacterial Agents Inhibiting the Energy-Coupling Factor (ECF) Transporters by Structure-Based Virtual Screening

2020 ◽  
Author(s):  
Eleonora Diamanti ◽  
Inda Setyawati ◽  
Spyridon Bousis ◽  
leticia mojas ◽  
lotteke Swier ◽  
...  
Keyword(s):  
Virtual Screening ◽  
Antibacterial Agents ◽  
Antimicrobial Agents ◽  
Energy Coupling ◽  
Coupling Factor ◽  
Design Synthesis ◽  
Screening Design ◽  
Starting Point ◽  
Wide Range ◽  
Vitamin Uptake

Here, we report on the virtual screening, design, synthesis and structure–activity relationships (SARs) of the first class of selective, antibacterial agents against the energy-coupling factor (ECF) transporters. The ECF transporters are a family of transmembrane proteins involved in the uptake of vitamins in a wide range of bacteria. Inhibition of the activity of these proteins could reduce the viability of pathogens that depend on vitamin uptake. Because of their central role in the metabolism of bacteria and their absence in humans, ECF transporters are novel potential antimicrobial targets to tackle infection. The hit compound’s metabolic and plasma stability, the potency (20, MIC Streptococcus pneumoniae = 2 µg/mL), the absence of cytotoxicity and a lack of resistance development under the conditions tested here suggest that this scaffold may represent a promising starting point for the development of novel antimicrobial agents with an unprecedented mechanism of action.<br>

Evaluation and Avoidance of False Alarm by Controlling Rhine Water with Continuously Working Biotests

1994 ◽  
Vol 29 (3) ◽  
pp. 207-209 ◽  
Author(s):  
H. Puzicha
Keyword(s):  
Warning System ◽  
Point Sources ◽  
Trophic Levels ◽  
River Rhine ◽  
Wide Range ◽  
River Test ◽  
Continuous Working ◽  
Range Of Variation ◽  
Contaminant Load ◽  
Rhine Water

Effluents from point sources (industries, communities) and diffuse inputs introduce pollutants into the water of the river Rhine and cause a basic contaminant load. The aim is to establish a biological warning system to detect increased toxicity in addition to the already existing chemical-physical monitoring system. To cover a wide range of biocides, continuous working biotests at different trophic levels (bacteria, algae, mussels, water fleas, fishes) have been developed and proved. These are checked out for sensitivity against toxicants, reaction time, validity of data and practical handling under field conditions at the river. Test-specific appropriate methods are found to differentiate between the normal range of variation and true alarm signals.

scholarly journals Consumer Neuroscience Techniques in Advertising Research: A Bibliometric Citation Analysis

2021 ◽  
Vol 13 (3) ◽  
pp. 1589
Author(s):  
Juan Sánchez-Fernández ◽  
Luis-Alberto Casado-Aranda ◽  
Ana-Belén Bastidas-Manzano
Keyword(s):  
Self Report ◽  
Future Research ◽  
Complex Nature ◽  
Clear Understanding ◽  
Continuous Growth ◽  
Main Research ◽  
Consumer Neuroscience ◽  
Starting Point ◽  
Wide Range ◽  
Performance Analysis Tools

The limitations of self-report techniques (i.e., questionnaires or surveys) in measuring consumer response to advertising stimuli have necessitated more objective and accurate tools from the fields of neuroscience and psychology for the study of consumer behavior, resulting in the creation of consumer neuroscience. This recent marketing sub-field stems from a wide range of disciplines and applies multiple types of techniques to diverse advertising subdomains (e.g., advertising constructs, media elements, or prediction strategies). Due to its complex nature and continuous growth, this area of research calls for a clear understanding of its evolution, current scope, and potential domains in the field of advertising. Thus, this current research is among the first to apply a bibliometric approach to clarify the main research streams analyzing advertising persuasion using neuroimaging. Particularly, this paper combines a comprehensive review with performance analysis tools of 203 papers published between 1986 and 2019 in outlets indexed by the ISI Web of Science database. Our findings describe the research tools, journals, and themes that are worth considering in future research. The current study also provides an agenda for future research and therefore constitutes a starting point for advertising academics and professionals intending to use neuroimaging techniques.

Energy-minimization multiscale based mesoscale modeling and applications in gas-fluidized catalytic reactors

2019 ◽  
Vol 35 (8) ◽  
pp. 879-915 ◽  
Author(s):  
Bona Lu ◽  
Yan Niu ◽  
Feiguo Chen ◽  
Nouman Ahmad ◽  
Wei Wang ◽  
...  
Keyword(s):  
Energy Minimization ◽  
Fluid Model ◽  
Scale Up ◽  
Flow Characteristics ◽  
Chemical Kinetic ◽  
Mesoscale Modeling ◽  
Catalytic Reactors ◽  
Chemical Kinetic Model ◽  
Starting Point ◽  
Wide Range

Abstract Gas-solid fluidization is intrinsically dynamic and manifests mesoscale structures spanning a wide range of length and timescales. When involved with reactions, more complex phenomena emerge and thus pose bigger challenges for modeling. As the mesoscale is critical to understand multiphase reactive flows, which the conventional two-fluid model without mesoscale modeling may be inadequate to resolve even using extremely fine grids, this review attempts to demonstrate that the energy-minimization multiscale (EMMS) model could be a starting point to develop such mesoscale modeling. Then, the EMMS-based mesoscale modeling with emphasis on formulation of drag coefficients for different fluidization regimes, modification of mass transfer coefficient, and other extensions are discussed in an attempt to resolve the emerging challenges. Its applications with examples of development of novel fluid catalytic cracking and methanol-to-olefins processes prove that the mesoscale modeling plays a remarkable role in improving the predictions in hydrodynamic behaviors and overall reaction rate. However, the product content primarily depends on the chemical kinetic model itself, suggesting the necessity of an effective coupling between chemical kinetics and flow characteristics. The mesoscale modeling can be believed to accelerate the traditional experimental-based scale-up process with much lower cost in the future.

scholarly journals Development of Permeability Models for Saturated Fluid Flow across Arrays of Fibre Clusters

2002 ◽  
Vol 11 (3) ◽  
pp. 096369350201100
Author(s):  
E.M. Gravel ◽  
T.D. Papathanasiou
Keyword(s):  
Analytical Models ◽  
Dual Porosity ◽  
Hydraulic Permeability ◽  
Fibrous Media ◽  
Fibre Bundles ◽  
Hexagonal Packing ◽  
Composites Manufacturing ◽  
Starting Point ◽  
Wide Range ◽  
Flow Through

Dual porosity fibrous media are important in a number of applications, ranging from bioreactor design and transport in living systems to composites manufacturing. In the present study we are concerned with the development of predictive models for the hydraulic permeability ( Kp) of various arrays of fibre bundles. For this we carry out extensive computations for viscous flow through arrays of fibre bundles using the Boundary Element Method (BEM) implemented on a multi-processor computer. Up to 350 individual filaments, arranged in square or hexagonal packing within bundles, which are also arranged in square of hexagonal packing, are included in each simulation. These are simple but not trivial models for fibrous preforms used in composites manufacturing – dual porosity systems characterised by different inter- and intra-tow porosities. The way these porosities affect the hydraulic permeability of such media is currently unknown and is elucidated through our simulations. Following numerical solution of the governing equations, ( Kp) is calculated from the computed flowrate through Darcy's law and is expressed as function of the inter- and intra-tow porosities (φ, φt) and of the filament radius ( Rf). Numerical results are also compared to analytical models. The latter form the starting point in the development of a dimensionless correlation for the permeability of such dual porosity media. It is found that the numerically computed permeabilities follow that correlation for a wide range of φ i, φt and Rf.

Analysis and Test on Mechanical Properties of a Flexible Suspension Bridge

2013 ◽  
Vol 405-408 ◽  
pp. 1616-1622
Author(s):  
Guo Hui Cao ◽  
Jia Xing Hu ◽  
Kai Zhang ◽  
Min He
Keyword(s):  
Mechanical Properties ◽  
Suspension Bridge ◽  
Experimental Results ◽  
Suspension Bridges ◽  
Loading Test ◽  
Main Cable ◽  
Element Simulation ◽  
Static Loading Test ◽  
Geometric Nonlinear Analysis ◽  
Test Process

In order to research on mechanical properties of flexible suspension bridges, a geometric nonlinear analysis method was used to simulate on the experimental results, and carried on static loading test finally. In the loading test process, the deformations were measured in critical section of the suspension bridge, and displacement values of measured are compared with simulation values of the finite element simulation. Meanwhile the deformations of the main cable sag are observed under classification loading, the results show that the main cable sag increment is basically linear relationship with the increment of mid-span loading and tension from 3L/8 and 5L/8 to L/2 section, the main cable that increasing unit sag required mid-span loads and tension are gradually reduce in near L/4 and 3L/4 sections and gradually increase in near L/8 and 7L/8 sections and almost equal in near L/2, 3L/8 and 5L/8 sections. From the experimental results, the flexible suspension bridge possess good mechanical properties.

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